


Miku's Big Concert

by Gothdresser



Category: Vocaloid
Genre: Concert, Diaper, F/F, Fatty - Freeform, Kissing, Panty Poop, Soiling, Weight Gain, Yuri, diapermessing, hand holding, messing, peeing, pissing, pooping, public embarrassment
Language: English
Status: Completed
Published: 2019-06-23
Updated: 2019-06-23
Packaged: 2020-05-16 19:31:21
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,059
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19324636
Author URL: https://archiveofourown.org/users/Gothdresser/pseuds/Gothdresser
Summary: Hatsune Miku is a big star on the stage, emphasis on 'big', and the bigger the butt, the bigger the mess~Aiming for one more story this month, although surprisingly not fatty, so enjoy~





	Miku's Big Concert

Pulling up her panties around her large butt, Miku sighed as she had just pushed out another large mess. Her weight had been getting to her ever since she packed on more than a few pounds, and accidents were all too common if she didn’t use the bathroom enough. There was always one problem with using toilets though if she did somehow manage to position her fat ass on it right… Miku pushed the handle of the toilet down, praying it would work this time, but a couple of more attempts at flushing caused her to have to back up. Water was overflowing from the toilet once again and all Miku could do was throw down a couple of towels and close the bathroom door in her dressing room. She hated leaving it like that but calling someone to fix it was terribly embarrassing and she had a show to do. At least she had emptied herself out as well as she could before she had to go on stage, but her tummy rumbled again as she left the dressing room.  


Miku had to watch her breathing as she lumbered out toward the stage, feeling the tightness of her outfit as she waddled her massive rear. Her clothes used to feel so loose and airy, but after adding dozens of pounds of lard to her formerly svelt frame, they were a terribly tight squeeze! Air still lapped at the back of her thighs since her thick legs were pretty squished by her thigh highs, certainly not helped by how short her skirt was as if it was a couple of sizes too short, almost enough to show off the XXXL panties clad on her big fat ass. Not to mention her shirt looked more like an oversized bra with how much her fat, I-cup or possibly bigger breasts filled it out while she had quite the muffin top with her obese stomach hanging over the waistband of her skirt. Tighter detached sleeves to be more stylish and sleek backfired with her enlarged size as well as they tightly hugged her arms, looking ready to tear if Miku tried to flex too hard.  


And even despite this massive difference in size from when she started, it seemed that her popularity grew with her weight and her fans loved that there was more of her to worship. Idolatry of her and her fellow idols was compared to standards of the Greeks or the Renaissance. She was now the big beautiful Miku that everyone cheered for when she finally managed to get her big butt on stage, beginning her songs and dance routines. Her movements were nowhere near as flashy or athletic as they used to be, but Miku still put on her show, even if she had to be careful to avoid moving in odd ways. It wouldn’t be the first time her clothes tore during one of her shows, usually her sleeves or thigh highs, but a gratuitous picture of her back flab still circulated around the internet. She definitely always tried to avoid wardrobe malfunctions while her fattiness was a threat to that, but the show had to go on as Miku raised her arms and twisted her body as much as it would let her, praying she would be safe once again.  


The only problem was that her stomach rumbled again and her singing stuttered while she tried to sing louder to cover up the tummy troubles. Usually, she managed to avoid this complication by using the bathroom right before the show, but since she got heavier and heavier, Miku found her asshole puckering while trying to keep control of it. Her routine didn’t account for accidents though, and as Miku found herself squatting down as much as she could in preparation for a jump that wouldn’t work out. Not because of the weight of her body, but rather the weight exiting it as Miku grit her teeth, feeling her ass warm up and sag more as she rose back to standing position. Singing was much harder to focus on now as she interrupted herself with the moans of emptying out so heavily into her panties, her body shaking as the size of the mess surpassed the size of one, then two, and finally three chocolate cakes.  


Only then did her anus cut off the thick rope of shit that invaded her undies as Miku could barely begin to waddle backward off-stage. The red that overtook her face heavily contrasted the rest of her pale complexion, the girl yet again feeling embarrassed that she shit herself live in front of millions, and on camera on top of it all, the lights all on her only making her feel more nervous about getting caught at any second. Miku couldn’t even walk right, trying in vain to turn around to flee more quickly off of the stage, hearing a tear as she came tumbling down to land on her overweight stomach. The pressure of hitting the wood of the stage pushed out all of the remaining mess in her that didn’t come out before, the mushy mess pouring into her overfilled panties and some of the less-solid mess began to leak down her thighs. It was hard to even count however many cakes she could’ve had shoved into her underwear, the white of her shimapan panties stained to be brown-and-blue stripes, miraculously holding in the humongous mess.  


Miku wasn’t even able to get herself back up onto her feet as the music began to slow to a stop, only her grunts of both messing herself and trying to get up coming across the speakers. Her humiliation was endless as all her attempts to stand up were futile with the weight of her body and the mess, crawling on her hands and knees while dragging the bloated panties behind her. Her tears were even interrupted with more moaning as squishing and squelching came over the microphone again. She was easily aware of the eyes on her, especially all the stagehands that came close to help her but recoiled from the smell, the crowd of employees parting to let the big potty pants crawl to her dressing room. It wasn’t hard to have noticed the bulging eyes when people saw Miku’s size alone, but she wasn’t used to this level of shame where she could hear the quiet murmuring all focused on her weight and mess. They pinched their noses and turned away as Miku whimpered once again, leaving a trail of piss and tears behind her as she finally managed to drag her fat ass and the mess sticking to it all the way to her dressing room.  


Trying to use the couch in the dressing room to stand up was practically impossible, the mess between her legs making her already lumbering movements even more tricky to handle. Miku had to waddle her way inch by inch through the dressing room to reach her spare clothes, but the sound of her personal bathroom’s door slamming shut behind her forced her to wiggle around to see her fellow pink-haired idol. “H-hello, Luka. Are you o-... um, okay…?”  


Squeezing her butt through the bathroom door, Luka’s rear told the story pretty easily with her usual skirt draped over the protruding accident, her fat butt swollen even more with the massive mess clinging between her asscheeks. Even if it was only a single mess, it put Miku’s earlier accident to shame, not only because of the sheer size of it, but also that it shaped her butt so well. Luka’s fat ass looked even fatter with the waste that sat between her enormous crack. “I see no one came to unclog the toilet, although I imagine they’d need to invest in a new one with how much I know you can shit. Do you see this, Miku?” Pointing to the mess behind her, it was almost impossible not to notice how much Luka had shit herself, for both the size and smell of it, even if Miku’s mess canceled it out here. “This happened because you had to ruin yet another toilet, even though I told you to just wear diapers already. What do you have to say for yourself?”  


Her heart raced as she hadn’t even been given a chance to calm down this the intense public humiliation that she had just suffered, her heavy thighs shaking as Miku floundered an excuse. “But diapers are so… so… childish for an idol! I don’t think fans would want to see me shaking around my butt with a diaper it.” Miku couldn’t even tell if her fans were there for her cuteness or her sexiness or her fatness when her weight was this high, but she had to take a guess they weren’t there to see a baby perform in her pants on stage.  


“And yet tonight you utterly shit in front of all those fans, crying and crapping your panties even more as you crawled that bulging butt offstage. Is your loose fat ass what you want your fans to see, for them to rave about on the internet of how much their favorite idol can blow out her panties?” Arms somewhat crossed for what a plump woman like Luka could manage, she made her point as she walked away from the bathroom to sit her soiled rear down on the couch with a loud squish. “I told you time and time again this would happen, and you always said you could easily just be careful. It seems that time has passed since no doubt pictures of you dragging that fat sack of shit hanging around your waist off-stage are circulating by now.”  


“E-eeeeeh?! It just happened just half an hour ago though…” There was no way Miku could even try to hide it or cover it up if it was already appearing on the web, but it seemed news circulated much faster than she had expected. She had taken her time in crawling to her room, enough for Luka to also have an accident, although nowhere near as bad as Miku’s multiple messes. “I had enough trouble with all the news about my weight, but not my continence too. Everyone’s gonna hate me now…”  


“Oh come on, Miku. You still have me, don’t you?~” Even in the most hopeless of times, Luka still took her chances, especially for someone she had her eye on for quite a while. She hadn’t planned on seeing Miku fatten up with her, but she wasn’t one to miss an opportunity like this, especially after a scolding. “Who else do you think would be willing to help change your big bulging butt? Neither Len nor Rin can even change themselves, and I doubt their immature butts would want to help with a mess that large. I wonder who that leaves it up to... Unless you want to try getting out of those panties yourself~”  


There was only one answer, of course, and Miku was looking right at her. “F-fine. Can you please help me change my panties, Luka?” Once more there was the disparity between the color of her hair and how deeply Miku blushed at the statement. She wasn’t even really sure how she was getting out of these panties by herself and judging by the reaction of everyone on the way to her dressing room, she’d be getting no help from them.  


“Of course, of course, just waddle that massive mucky butt of yours over to me and I’ll make sure you’re well taken care of.” Lifting herself off the couch, Luka barely had to steady herself as a mess in the back of her panties wasn’t unusual at all for her, whether in public or private. She was lucky Miku was right there and didn’t have to move very far, but if only there was more of a height difference between them to make this easier, but… “Sorry, Miku~”  


Feeling heavy arms push her, Miku was knocked back onto her mess, as if she now was sitting on a bean bag. “E-eh? I thought I was getting a change, now I can’t even get up again!” Her chubby arms and legs outstretched as far as they could go, Miku wiggled like a turtle on its back, struggling her hardest despite how futile it was. “What’s even the point of this? This just makes it ha-hmmph!”  


Miku’s eyes went wide as suddenly she found her mouth filled with another’s tongue, whimpering as she struggled to breathe through her nose before the kiss finally broke. Panting for air while she lifted her head, Luka had quite the smirk on her face as she leaned in towards Miku as much as her stomach would let her. “You thought I was going to change you for free? Do you know how much work it’ll be just to get you out of that thing, let alone into a diaper? Because I’m sure as hell not letting you out of this without some padding to cushion your butt. Don’t worry, I’m sure you’ll grow to love your diapers, Miku~”  


Taking in another kiss, Miku was much more prepared for this one as she felt her tongue relax around Luka’s. The pink-haired girl seemed like so much an expert in this that she almost wondered if she’d been stalking Miku like a predator of love. Her tummy did rumble again but Miku ignored it as she gasped from pulling out of the kiss, only to find herself back to exploring Luka’s mouth, her body feeling so hot. She lacked so much experience in this department after hearing about how fans wouldn’t love a taken idol, but Miku felt at ease in the grip of Luka’s mouth and fattened arms. Too relaxed though as she felt herself squishing noisier and rising higher to press even more against Luka, her belly smushing and conforming against Luka’s. There was something too pleasurable about shitting herself just then, as all those other accidents were just messes, but this last one was special. She had crapped her panties for the, uh… um, well, she had lost count by now, but it was when Miku was kissing and embracing Luka, so that’s all that counted to her.  


Finally, after it felt like forever had gone by, Luka and Miku released each other from their grips, a quick look at the wall revealing it hadn’t even been five minutes, yet both girls were tuckered out. While Miku just leaned against her beanbag of crap, Luka sat back down on the couch with a loud squish before raising one buttcheek in the air. A groan turned into a moan as what sounded like a fart at first was accompanied by something far more mushy and messy. “Hehe, seems that came a little late, but all that kissing is quite tiring~ You had it worse though, don’t think I didn’t notice your mess had grown larger during all that~”  


The accusation was impossible to defend against as Miku nervously wiggled some more in her mess, feeling how much there was around and in between her butt cheeks. It was gross but somehow it felt more than amazing when Luka’s lips were against her own. This level of messing and the humiliation that surrounded it was something she definitely didn’t want to experience again, at least not alone like when she struggled off the stage. Maybe if she had Luka with her… Giggling at the thought of ever messing herself on stage like that again, Miku did have a more pressing issue: The mess pressing against her behind. “So yeah, how about that change you mentioned?”  


“Sure, just give me, hrrrrng… ahhhhh, a moment~” Dopey smile on her face, Luka lifted her rear off the couch to help change Miku as she felt it expanding the farther her fat ass got off of it. “Good thing I make sure to carry extra diapers because there’s no way I’m going back out there like this. I have my own set soon enough and a change for a change is only fair.”  


“Fine… but only a diaper this once, okay?”  


“As you wish~”

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Turning her head to the side, a smile widened on her chubby cheeks as she saw her partner with her, the duet going amazingly as always, especially since she so very much loved to do them with Luka. This time particularly since they were performing a song during Luka’s anniversary of an idol. Such a special time and they were only going to make it even more special as they wore matching dresses marked with their respective colors. The dresses even looked just about the same on their bulging bodies, normally loose but their similar sizes made the outfits so tight around the chest. Down below was different though as the dresses were quite airy and their moving hips easily showed their panties off to the crowd… Or what normally would’ve been panties, at least. Instead, their fans cheered at the ass shots of their diapers, unsoiled for now but her and Luka were about to change that.  


Hand-in-hand, both the fatties squatted down as they readied to jump for joy, but Miku and Luka both knew what was going to happen. Flashing a smile to each other with the fat of their thighs pressing against their calves, their mics caught their satisfying sighs of relief as their padded undies quickly sagged below their dresses. Miku could feel herself panting as all that thick shit was coming out of her, a squeeze at her hand as she made sure to push out all that she could even as she heard the squish of her mess hitting the stage already. Moving up to jump, the pair held the hands together in the air, their respective orange and blue scrunchies falling back as neither of them could get even an inch off the ground. Their butts landed with resounding crinkles and squelching as Miku and Luka just giggled to each other, wiggling their legs in the air as the sound of camera went off. Guess they’d be in the headlines again with their messy diapers, simple white with an overwhelmingly large brown bulge for Luka and Miku with her favorite shimapan-styled diapers, the blue-and-white design interrupted by a bulging splotch of blue-and-brown stripes.


End file.
